While the tour will still be on the road from mid-July through early September, the new U.S. stops--which include the Los Angeles, Indianapolis, Atlanta, Tampa and St. Louis areas, among many others--have been dropped into some gaps in the schedule. The full itinerary is below.

The roadwork supports Lavigne's sophomore album, last year's "Under My Skin." The double-platinum set features the cuts "Don't Tell Me," "My Happy Ending" and "Nobody's Home."

Lavigne, who co-wrote the new album's 12 tracks, collaborated with producers Butch Walker (of the Marvelous 3), Raine Maida (of Our Lady Peace), Don Gilmore (Linkin Park, Pearl Jam), Ben Moody (formerly of Evanescence) and singer-songwriter Chantal Kreviazuk. Lavigne's former guitarist, Evan Taubenfeld, co-wrote much of the material with her.

Earlier this month, Lavigne took home three Juno Awards: Artist of the Year, Pop Album of the Year and the Fan Choice Award. She also won Favorite Female Singer at the 18th Annual Kids' Choice Awards.

"Under My Skin" is the follow up to Lavigne's 2002 debut, "Let Go," which hit No. 1 on The Billboard 200 album chart, and has sold more than 15 million copies worldwide, according to RCA Records.

Lavigne is scheduled to make two television appearances in the midst of her tour: Aug. 12 on The Tonight Show with Jay Leno and Aug. 26 on Good Morning America.